The present disclosure relates to a method for determining the vertical position of at least a point of a ground portion using a work machine comprising an implement. Moreover, the present disclosure relates to a method for leveling a ground area using a work machine comprising an implement. Further, the present disclosure relates to a method for determining a volume of a material entity that is moved from a material body by an implement of a work machine. Additionally, the present disclosure relates to each one of a computer program, a computer readable medium, an electronic control unit, a work machine control system and a work machine.
When performing ground modifying operations, such as leveling or material moving operations such as excavating, using a work machine, it may be desired to obtain information as regards the position of a ground portion that has been modified or which is to be modified.
To this end, U.S. Pat. No. 5,996,702 proposes a method for operating a work machine tool in which the location of at least a portion of the work machine tool is determined and used for estimating an end result of the work machine tool operation.
However, it would be desired to improve the method as proposed in U.S. Pat. No. 5,996,702.
It is desirable to provide a reliable and/or versatile method for obtaining information as regards the position of a ground portion.
As such, the present disclosure relates to a method for determining the vertical position of at least a point of a ground portion using a work machine comprising an implement. The work machine further comprises position determining means adapted to determine at least the vertical position of the implement and force determining means adapted to determine a force applied to the implement.
The method comprises:
determining a contact force value indicative of a contact force between the ground portion and the implement using the force determining means;
determining whether or not the contact three value is within a predetermined contact force value range, and
if it is determined that the contact force value is within the predetermined contact force value range, using the position determining means for determining at least the vertical position of a portion of the implement which is in contact with the ground portion.
The above method implies a reliable way of determining whether or not at least a portion of the implement is in contact with the ground portion. This in turn implies that reliable information may be obtained, as regards the ground portion position.
As used herein, the expression “range” is intended to encompass closed ranges as well as open ranges. For instance, an open range may have an endpoint the absolute value of which is infinity resulting in that the above discussed feature of determining whether or not the contact force value is within a predetermined contact force value range corresponds to a feature of determining whether or not the absolute value of the contact three value is equal to or above a predetermined contact force value threshold value.
Optionally, the work machine comprises means for moving the implement, the method further comprising:
moving the implement until the contact force value is within the predetermined contact force value range.
The above features imply an appropriate manner of obtaining a desired contact force value.
Optionally, the work machine comprises means for moving the implement in at least a vertical direction.
Optionally, an end point of the predetermined contact force value range is indicative of the weight of the implement.
Optionally, the work machine comprises an implement load sensor, and wherein the feature of determining a contact force value comprises using the implement load sensor.
A work machine may be furnished with an implement load sensor for other purposes, e.g. to determine a weight of a load in the implement. As such, the use of the implement load sensor implies that the method according to the present disclosure may be performed without necessarily having to furnish the work machine with an additional sensor the sole purpose of which is to determine the contact force between the ground portion and the implement.
Optionally, the method further comprises transmitting the vertical position to a data receiver.
Optionally, the method further comprises:
determining the horizontal position of a portion of the implement and transmitting the horizontal position to the data receiver.
Optionally, the method further comprises:
using a global navigation satellite system and/or a total station for determining the horizontal position.
Optionally, the implement comprises a material receiving portion, adapted to receive material, and a surrounding portion, adapted not to receive material, the feature of determining a contact force value comprising determining a contact force value indicative of the contact force between the ground portion and a portion of the surrounding portion of the implement.
A second aspect of the present disclosure relates to a method for leveling a ground area using a work machine comprising an implement. The method comprises:
applying a predetermined portion of the implement to the ground portion to thereby level it, and
determining the vertical position of at least a point of a ground portion using the method according to the first aspect of the present disclosure.
The second aspect of the present disclosure implies an appropriate way to determine at least the vertical position of a leveled ground portion. For instance, at least the vertical position may be determined using the same tool, viz the implement, as has been used for the leveling procedure.
A third aspect of the present disclosure relates to a method for determining a volume of a material entity that is moved from a material body by an implement of a work machine, the method comprising:
firstly determining the vertical position of at least a point of a ground portion using the method according to the first aspect of the present disclosure and thereafter;
moving the material entity from the material body using the implement, the material entity comprising the ground portion,
determining at least the vertical position of a material body surface remaining after the implement has moved through the material body, and
determining the volume of the material entity using the vertical position of the ground portion and the vertical position of the material body surface.
The third aspect of the present disclosure implies an appropriate way to determine at least the vertical position of the ground portion before a material moving operation commences. For instance, at least the vertical position may be determined using the same tool, viz the implement, as will be used for the material moving procedure.
Optionally, the method comprises:
firstly determining the vertical position of a plurality of points of the ground portion using the method according to the first aspect of the present disclosure to thereby generate a ground portion surface estimate.
A fourth aspect of the present disclosure relates to a computer program comprising program code means for performing the computing steps of the first, second or third aspects of the present disclosure when the program is run on a computer.
A fifth aspect of the present disclosure relates to a computer readable medium carrying a computer program comprising program code means for performing the computing steps of the first, second or third aspects of the present disclosure when the program product is run on a computer.
A sixth aspect of the present disclosure relates to an electronic control unit for a work machine comprising an implement, the work machine further comprises position determining means adapted to determine at least the vertical position of the implement and force determining means adapted to determine a force applied to the implement, the electronic control unit being adapted to:
determine a contact force value indicative of a contact force between the ground portion and the implement using the force determining means;
determine whether or not the contact force value is within a predetermined contact force value range, and
if it is determined that the contact force value is within the predetermined contact force value range, use the position determining means for determining at least the vertical position of a portion of the implement which is in contact with the ground portion.
A seventh aspect of the present disclosure relates to a work machine control system comprising an electronic control unit according to the sixth aspect of the present disclosure.
An eighth aspect of the present disclosure relates to a work machine comprising a work machine control system according to the seventh aspect of the present disclosure.
It should be noted that the appended drawings are not necessarily drawn to scale and that the dimensions of some features of the present invention may have been exaggerated for the sake of clarity.